Euphoria is a simple, flexible, easy-to-learn programming language. It lets you quickly and easily develop programs for Windows, Linux, FreeBSD, NetbSD, OpenBSD, and Mac OS X. Although Euphoria provides subscript checking, uninitialized variable checking, and numerous other run-time checks, it is extremely fast and has the ability to compile to transparently compile native executables via C code.
ICI is a general purpose interpretive programming language that has dynamic typing and flexible data types with the flow control constructs and operators of C. It is designed for use in many environments, including embedded systems, as an adjunct to other programs, as a text-based interface to compiled libraries, and as a cross-platform scripting language with good string-handling capabilities.
Q is a powerful and extensible functional programming language based on the term rewriting calculus. When programming with Q, you specify a system of equations which the interpreter uses as rewrite rules to reduce expressions to normal form. Q is useful for scientific programming and other advanced applications, and also as a sophisticated kind of desktop calculator. The distribution includes the Q programming tools, a standard library, add-on modules for interfacing to various third-party libraries, and an Emacs mode.
STklos is a free Scheme System conforming to R5RS. The implementation is based on an ad-hoc Virtual Machine. It can also be compiled as a library, so that one can easily embed it in an application. Its features include an efficient and powerful object system based on CLOS, a simple-to-use module system, implementation of the full tower of numbers defined in R5RS, and easy connection to the GTK+ toolkit. STklos is the successor of STk, a Scheme interpreter tightly connected to the Tk toolkit.
The Glasgow Haskell Compiler is a robust, fully-featured, optimising compiler for the functional programming language Haskell. GHC compiles Haskell to either native code or C. It implements numerous experimental language extensions to Haskell for example concurrency, a foreign language interface, several type-system extensions, exceptions, and so on. GHC comes with a generational garbage collector, a space and time profiler, and a comprehensive set of libraries.
Steel Bank Common Lisp is a development environment for Common Lisp, with excellent support for the ANSI standard: garbage collection, lexical closures, powerful macros, strong dynamic typing, incremental compilation, and the famous Common Lisp Object System (multimethods and all). It also includes many extensions, such as native threads, socket support, a statistical profiler, programmable streams, and more. These are all available through an integrated, interactive native compiler which feels like an interpreter. SBCL is unique in being a multiplatform native compiler which bootstraps itself completely from source, using a C compiler and any other ANSI Common Lisp implementation.
Onyx is a powerful stack-based, multi-threaded, interpreted, general purpose programming language similar to PostScript and Forth. It can be embedded as an extension language into other applications, and was designed to have a small memory footprint. It is among the smallest embeddable interpreters available.